Systems and methods for producing engineered fuel feed stocks from waste material

ABSTRACT

Systems and methods for producing engineered fuels from solid waste material are described herein. In some embodiments, a method includes receiving a waste stream at a multi-material processing platform and separating the waste stream to remove non-processable waste and marketable recyclables. The method further includes conveying processable materials to a material classification system and incorporating additives to produce an engineered fuel from the constituents of the waste stream.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalApplication Ser. No. 61/493,071, entitled “Systems, Methods andProcesses for Granulating Heterogeneous Waste Streams for EngineeredFuel Feedstock Production,” filed Jun. 3, 2011, and U.S. ProvisionalApplication Ser. No. 61/645,931, entitled “Systems and Methods forProducing Engineered Fuel Feed Stocks From Waste Material,” filed May11, 2012, each of which is incorporated herein by reference in itsentirety.

This application is also related to U.S. patent application AttorneyDocket No. RECM-022/02US 314670-2115, entitled “Systems and Methods forProcessing a Heterogeneous Waste Stream,” filed Jun. 1, 2012, thedisclosure of which is incorporated herein in its entirety.

BACKGROUND

The disclosure relates to alternative fuels, chemicals, and fuel feedstocks. In particular, the disclosure relates to systems and methods forproducing an engineered fuel feed stock having additives to controlemissions, prevent corrosion, and/or improve operational performanceduring combustion or gasification applications. The feed stock describedherein includes at least one component of processed solid waste, anadditive, and optionally other components.

Sources of fossil fuels useful for heating, transportation, and theproduction of chemicals as well as petrochemicals are becomingincreasingly scarce and costly. Industries such as those producingenergy and petrochemicals are actively searching for cost-effectiveengineered fuel feed stock alternatives for use in generating thoseproducts and many others. Additionally, due to the ever increasing costsof fossil fuels, transportation costs for moving engineered fuel feedstocks for production of energy and petrochemicals is rapidlyescalating.

These energy and petrochemical producing industries, and others, haverelied on the use of fossil fuels, such as coal and oil and natural gas,for use in combustion and gasification processes for the production ofenergy, for heating and electricity, and the generation of synthesis gasused for the downstream production of chemicals and liquid fuels, aswell as an energy source for turbines.

One potentially significant source of feed stock for production of anengineered fuel is solid waste. Solid waste, such as municipal solidwaste (MSW), is typically disposed of in landfills or used in combustionprocesses to generate heat and/or steam for use in turbines. Thedrawbacks accompanying combustion include the production of pollutantssuch as nitrogen oxides, sulfur oxides, particulates and products ofchlorine that are damaging to the environment.

Thus, there is a need for alternative fuels that burn efficiently andcleanly and that can be used for the production of energy and/orchemicals. There is at the same time a need for waste management systemsthat implement methods for reducing green house gas emissions of wasteby utilizing such wastes. In particular, there is a need for improvedsystems and methods for sorting waste material and reclaiming a resourcevalue from components of the waste material. By harnessing and using theenergy content contained in waste, it is possible to reduce green housegas emissions and/or otherwise reduce emissions generated during theprocessing of wastes thereby effectively using the waste generated bycommercial and residential consumers.

SUMMARY

Systems and methods for producing engineered fuels from solid wastematerial are described herein. In some embodiments, a method includesreceiving a waste stream at a multi-material processing platform andseparating the waste stream to remove non-processable waste andmarketable recyclables. The method further includes conveyingprocessable materials to a material classification system andincorporating additives to produce an engineered fuel from theconstituents of the waste stream.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a method for producing an engineeredfuel feed stock from waste material, according to an embodiment.

FIG. 2 is a schematic illustration of a system for producing anengineered fuel feed stock from waste material, according to anembodiment.

FIG. 3 is a schematic illustration of a material classificationsubsystem included in the system illustrated in FIG. 2, according to anembodiment.

FIG. 4 is a schematic illustration of a material classificationsubsystem included in the system illustrated in FIG. 2, according to anembodiment.

FIG. 5 is a schematic illustration of a material classificationsubsystem included in the system illustrated in FIG. 2, according to anembodiment.

FIG. 6 is a schematic illustration of a material classificationsubsystem included in the system illustrated in FIG. 2, according to anembodiment.

FIG. 7 is a schematic illustration of a system for producing anengineered fuel feed stock from waste material, according to anembodiment.

FIG. 8 is a schematic illustration of a system for producing anengineered fuel feed stock from waste material, according to anembodiment.

FIGS. 9A-9F are top views of a fuel feed stock in a first, second,third, fourth, fifth, and sixth configuration, respectively, accordingto an embodiment.

FIG. 10 is a top view of a fuel feed stock in a first stage and in afirst, second, third, fourth, fifth, sixth, seventh, eighth, ninth, andtenth configuration, respectively, according to an embodiment.

FIG. 11 is a top view of the fuel feed stock illustrated in FIG. 10 in asecond stage and in a first, second, third, fourth, fifth, sixth,seventh, eighth, ninth, and tenth configuration, respectively.

DETAILED DESCRIPTION

Systems and methods for producing engineered fuels from solid wastematerial are described herein. In some embodiments, a method includesreceiving a waste stream at a multi-material processing platform andseparating the waste stream to remove non-processable waste, prohibitiveitems and marketable recyclables. The method further includes conveyingprocessable materials to a material classification system andincorporating additives to produce an engineered fuel from theconstituents of the waste stream.

The term “about” generally means plus or minus 10% of the value stated,e.g. about 5 would include 4.5 to 5.5, about 10 would include 9 to 11,about 100 would include 90 to 110.

The term “carbon content” means all carbon contained in the fixed carbon(see definition below) as well as in all the volatile matters in thefeed stock.

The term “commercial waste” means solid waste generated by stores,offices, restaurants, warehouses, and other non-manufacturing,non-processing activities. Commercial waste does not include household,process, industrial or special wastes.

The term “construction and demolition debris” (C&D) means uncontaminatedsolid waste resulting from the construction, remodeling, repair anddemolition of utilities, structures and roads; and uncontaminated solidwaste resulting from land clearing. Such waste includes, but is notlimited to bricks, concrete and other masonry materials, soil, rock,wood (including painted, treated and coated wood and wood products),land clearing debris, wall coverings, plaster, drywall, plumbingfixtures, non-asbestos insulation, roofing shingles and other roofcoverings, asphaltic pavement, glass, plastics that are not sealed in amanner that conceals other wastes, empty buckets ten gallons or less insize and having no more than one inch of residue remaining on thebottom, electrical wiring and components containing no hazardousliquids, and pipe and metals that are incidental to any of the above.Solid waste that is not C&D debris (even if resulting from theconstruction, remodeling, repair and demolition of utilities, structuresand roads and land clearing) includes, but is not limited to asbestoswaste, garbage, corrugated container board, electrical fixturescontaining hazardous liquids such as fluorescent light ballasts ortransformers, fluorescent lights, carpeting, furniture, appliances,tires, drums, containers greater than ten gallons in size, anycontainers having more than one inch of residue remaining on the bottomand fuel tanks Specifically excluded from the definition of constructionand demolition debris is solid waste (including what otherwise would beconstruction and demolition debris) resulting from any processingtechnique, that renders individual waste components unrecognizable, suchas pulverizing or shredding.

The term “fiber” means materials including, but not limited to,textiles, wood, biomass, papers, fiberboard and cardboard. In addition,the term “fibers” can refer to the aforementioned materials with a bulkdensity of about 4 pounds per cubic foot, and generally includenaturally occurring or man-made products based on woody, cellulostic orlignocellulostic biomass, plants and living stocks. In terms of chemicalcharacteristics, the fiber materials typically have a carbon content of35-50 wt. % with an average of about 45 wt. %, a hydrogen content of5-7% wt. % with an average of about 6 wt. %, an oxygen content of 35-45wt. % with an average of about 40 wt. %, and a higher heating value ofabout 6,000-9,000 Btu/lb with an average of about 7,500 Btu/lb, all in adry basis.

The term “fixed carbon” means the balance of material after moisture,ash, and volatile matter are excluded, as determined by proximateanalysis.

The term “garbage” means putrescible solid waste including animal andvegetable waste resulting from the handling, storage, sale, preparation,and cooking or serving of foods. Garbage originates primarily in homekitchens, stores, markets, restaurants and other places where food isstored, prepared or served.

The term “hard plastic”, also refered to as rigid plastic, means plasticmaterials including, but not limited to, high-density polyethylene,polyethylene terephthalate, and polyvinyl chloride. In addition, theterm “hard plastic” can refer to the aforementioned materials with abulk density of about 15-25 pounds per cubic foot and actual materialdensity of about 56-87 pounds per cubic foot.

The term “hazardous waste” means solid waste that exhibits one of thefour characteristics of a hazardous waste (reactivity, corrosivity,ignitability, and/or toxicity) or is specifically designated as such bythe EPA as specified in 40 CFR part 262.

The term “marketable recyclables” means materials for which there is anactive market where the materials can be sold as commodities, includingbut not limited to, old corrugated cardboard (OCC), old newspaper (ONP),mixed paper, high-density polyethylene (HDPE), polyethyleneterephthalate (PET), mixed plastics, ferrous metals, and/or nonferrousmetals, and glass.

The term “municipal solid waste” (MSW) means solid waste generated atresidences, commercial or industrial establishments, and institutions,and includes all processable wastes along with all components ofconstruction and demolition debris that are processable, but excludinghazardous waste, automobile scrap and other motor vehicle waste, usedtires, infectious waste, asbestos waste, contaminated soil and otherabsorbent media and ash other than ash from household stoves. Componentsof municipal solid waste include without limitation plastics, fibers,paper, yard waste, rubber, leather, wood, and also recycling residue, aresidual component containing the non-recoverable portion of recyclablematerials remaining after municipal solid waste has been processed witha plurality of components being sorted from the municipal solid waste.

The term “non-processable waste” (also known as noncombustible waste)means waste that does not readily gasify in gasification systems anddoes not give off any meaningful contribution of carbon or hydrogen intothe synthesis gas generated during gasification. Non-processable wastesinclude but are not limited to: batteries, such as dry cell batteries,mercury batteries and vehicle batteries; refrigerators; stoves;freezers; washers; dryers; bedsprings; vehicle frame parts; crankcases;transmissions; engines; lawn mowers; snow blowers; bicycles; filecabinets; air conditioners; hot water heaters; water storage tanks;water softeners; furnaces; oil storage tanks; metal furniture; propanetanks; and yard waste.

The term “processed MSW waste stream” means that MSW has been processedat, for example, a materials recovery facility, by having been sortedaccording to types of MSW components. Types of MSW components include,but are not limited to, plastics, including soft plastics and hardplastics (e.g, #1 to #7 plastics and other polymers such asAcrylonitrile-butadiene-styrene (ABS), Polyamide (also called nylon,PA), Poly(butylene terephthalate)—PBT), fibers, paper, yard waste,rubber, leather, wood, and also recycling residue, a residual componentcontaining the non-recoverable portion of recyclable materials remainingafter municipal solid waste has been processed with a plurality ofcomponents being sorted from the municipal solid waste. Processed MSWcontains substantially no glass, metals, or grit. Grit includes dirt,dust, and sand, and as such the processed MSW contains substantially nononcombustibles.

The term “processable waste” means wastes that is readily processable byequipment such as shredders, density separators, optical sorters, etc.and can be used as fuel feedstock in thermal and biological conversionprocesses. Processable waste includes, but is not limited to, newspaper,junk mail, corrugated cardboard, office paper, magazines, books,paperboard, other paper, rubber, textiles, and leather from residential,commercial, and institutional sources only, wood, food wastes, and othercombustible portions of the MSW stream.

The term “recycling residue” means the residue remaining after arecycling facility has processed its recyclables from incoming wastewhich cannot be marketed and thus no longer contains economic value froma recycling point of view.

The term “sludge” means any solid, semisolid, or liquid generated from amunicipal, commercial, or industrial wastewater treatment plant orprocess, water supply treatment plant, air pollution control facility orany other such waste having similar characteristics and effects.

The term “soft plastics” means plastic films, bags and foams, such aslow density polyethylene, expanded polystyrene, and extruded polystyrenefoam. In addition, the term “soft plastic” can refer to theaforementioned materials with a bulk density of about 1-4 pounds percubic foot and which are typically two-dimensional or flat in shape.

The term “solid waste” means unwanted or discarded solid material withinsufficient liquid content to be free flowing, including, but notlimited to rubbish, garbage, scrap materials, junk, refuse, inert fillmaterial, and landscape refuse, but does not include hazardous waste,biomedical waste, septic tank sludge, or agricultural wastes, animalmanure and absorbent bedding used for soil enrichment or solid ordissolved materials in industrial discharges. The fact that a solidwaste, or constituent of the waste, may have value, be beneficiallyused, have other use, or be sold or exchanged, does not exclude it fromthis definition.

The term “sorbent” means a material added to the engineered fuel feedstock that either acts as a traditional sorbent and adsorbs a chemicalor elemental by-product, or reacts with a chemical or elementalby-product, or in other cases, simply as an additive to alter the fuelfeed stock characteristics such as ash fusion temperature.

In some embodiments, a waste management system includes a tipping floor,a screen, a primary shredder, a secondary shredder, a set of separators,a material classification subsystem, and an engineered fuel productionsubsystem. In some embodiments, the tipping floor can be configured toreceive at least a portion of a waste stream to be processed within orby the waste management system. The screen is configured to process theincoming waste by removing undersized fraction of the waste consistingprimarily of non combustibles, batteries, and food waste. The primaryshredder is configured to shred the waste material to a predeterminedsize such that remaining non-processable and non-combustible waste canbe separated from the waste stream by the set of separators. The set ofseparators can include a magnetic separator, an eddy current separator,an optical separator, and/or a glass separator. The secondary shreddercan be configured to receive the processable waste stream and shred theprocessable waste to a predetermined size. The material classificationsubsystem can be configured to further separate (i.e., classify) theprocessable waste and deliver the classified waste to the engineeredfuel production subsystem. The engineered fuel production subsystem isconfigured to receive the classified waste material from the materialclassification subsystem and selectively produce an engineered fuel.

FIG. 1 is a flowchart illustrating a method 100 for producing anengineered fuel feed stock from solid waste material. The method 100includes conveying a waste stream to a multi-material processingplatform 102. In some embodiments, the waste stream can be, for example,MSW, recycling residue, and/or any combination thereof. In someembodiments, the waste stream can be delivered to a tipping floor of awaste material receiving facility. The method 100 includes separatingnon-processables and prohibitives 104 from the waste stream. In someembodiments, the non-processables can be removed from the waste streambefore the waste stream is conveyed to the tipping floor of the wastematerial receiving facility (e.g., at a previous waste handlingfacility).

The method 100 further includes separating marketable recyclables 106from the waste stream. The marketable recyclables can be separated usingany suitable method. In some embodiments, the marketable recyclables areseparated manually (e.g., by hand). In other embodiments, the wastestream can be fed into a separator and/or series of separators. Forexample, in some embodiments, the separators can include a magneticseparator (e.g., to remove ferrous metals), a disc separator (e.g., toremove relatively large pieces of OCC, ONP, mixed plastics, etc.), aneddy current separator (e.g., to remove non-ferrous metals), an opticalsorter separator and/or any other suitable separator (e.g. XRF sensorbased separator). In this manner, materials with a sufficiently highmarket value can be removed (e.g., separated) from the waste stream andfurther processed (e.g., bailed, stored, shipped, etc.) to be sold as amarketable material. Systems and methods of processing and sortingmarketable recyclables are described in U.S. Pat. No. 7,264,124 toBohlig et al., filed Nov. 17, 2004, entitled “Systems and Methods forSorting Recyclables at a Material Recovery Facility,” U.S. Pat. No.7,341,156 to Bohlig et al., filed Apr. 15, 2005, entitled “Systems andMethods for Sorting, Collecting Data Pertaining to and CertifyingRecyclables at a Material Recovery Facility,” and U.S. PatentPublication No. 2008/0290006 to Duffy et al., filed May 23, 2007,entitled “Systems and Methods for Optimizing a Single-Stream MaterialsRecovery Facility,” the disclosures of which are hereby incorporatedherein by reference, in their entireties.

With the non-processables, prohibitives and the marketable recyclablesremoved from the waste stream, the waste stream can be conveyed to amaterial classification subsystem 108. In some embodiments, theconveying of the waste stream can include passing the waste streamthrough at least one shredder configured to reduce the size of theconstituents of the waste stream. For example, in some embodiments, theshredder can be configured to reduce the size of the constituents of thewaste stream to be less than about 4 inches. In other embodiments, theshredder can be configured to reduce the size of the constituents of thewaste stream to be between about 0.75 inches and about 1 inch. In stillother embodiments, the shredder can be configured to reduce the size ofthe constituents of the waste stream to be between about 0.1875 inchesand about 0.25 inches. With the size of the constituents of the wastestream reduced, the conveying of the waste stream to the materialclassification subsystem can further include passing the waste streamthrough a set of separators. In some embodiments, the set of separatorscan include, for example, a density separator, a magnetic separator, aneddy current separator, a glass separator, and/or the like. For example,in some embodiments, the shredded waste stream can pass through adensity separator such that materials with a density below apredetermined threshold pass to the material classification subsystemand material with a density above the predetermined threshold pass to asecondary subsystem (e.g., further separated to remove marketablerecyclables not separated in the first separation process) and/or aredisposed of (e.g., conveyed to a landfill).

The material classification subsystem can be configured to furtherseparate a desired set of materials. For example, in some embodiments,the material classification subsystem receives a waste stream includinghard plastics, soft plastics, and/or fibers. In such embodiments, thematerial classification subsystem can separate the hard plastics, softplastics, and/or fibers via any suitable method. For example, in someembodiments, the material classification subsystem can include cyclonicseparators, fluidized beds, density separators, and/or the like. Withthe waste stream further separated by the material classificationsubsystem, the method 100 includes selectively mixing additive material110 to one or more components of the separated waste stream. Theadditive material can include, for example, chemical additives,sorbents, biomass waste (e.g., wood), biomaterials (e.g., animalmanure), and/or any other suitable additive. With the additive materialmixed with at least a portion of the waste stream, the portion of thewaste stream can be processed into an engineered fuel feed stock 112.

In some embodiments, at least a portion of the waste stream and theadditive material can be compressed to form a densified intermediatematerial. The densified intermediate material can be in the form ofcubes, briquettes, pellets, honeycomb, or other suitable shapes andforms. For example, in some embodiments, chemical additives (e.g.,sorbents, nutrients, promoters, and/or the like) can be mixed with hardplastics and/or soft plastics that have been separated from the wastestream by the material classification subsystem, and then compressed toform pellets such that the additives are evenly distributed (i.e.,substantially homogeneous) and integrated (i.e., bound) within theplastic pellets. In some embodiments, the densified intermediatematerial can be used as an engineered fuel feed stock in, for example,combustion power plants (e.g., coal burning power plants). In otherembodiments, the densified intermediate material can be combined with asecond portion of the waste stream (e.g., the soft plastic and/or thefiber) and processed (e.g., compressed). In still other embodiments, thedensified intermediate material can be granulated and/or pulverized toany suitable particle size, combined with a second portion of the wastestream and/or additional additives, and then compressed to form adensified engineered fuel feed stock. In this manner, the constituentsof the separated waste stream (e.g., the constituents of the wastestream after material classification) can be combined with additives(and/or portions of previously processed materials) to produce asubstantially homogeneous engineered fuel feed stock that includesinseparable additives, as described in further detail herein.

FIG. 2 is a schematic illustration of a system 200 for producing anengineered fuel feed stock from solid waste material. The system 200includes at least a tipping floor F, a primary shredder 230, a secondaryshredder 235, a density separator 243, a magnetic separator 244, an eddycurrent separator 245, a glass separator 246, a material classificationsubsystem 220, and a fuel feed stock production subsystem 280 (alsoreferred to herein as “engineered fuel subsystem 280” or “EF subsystem280”). In some embodiments, a waste stream is conveyed to the tippingfloor F, as shown by arrow AA. The waste stream can be, for example, MSWdelivered via a collection truck or recycling residue from a recyclingfacility. In other embodiments, the solid waste can be delivered via aconveyer from a material recovery facility or other waste handlingfacility.

The waste stream, at least partially disposed on the tipping floor F, isconfigured to be separated such that non-processables, prohibitivesand/or marketable recyclables (as described above) are removed (e.g.,separated) from the waste stream. In some embodiments, the tipping flooris configured to have manual removal of bulky items, screen separatorsto remove undersized materials such as batteries, electronic parts, foodwaste, and noncombustibles.

While not shown in FIG. 2, the system 200 can include any number ofconveyers and/or transport mechanisms configured to convey at least aportion of the waste stream from a portion of the system 200 to a secondportion of the system 200. In this manner and with the non-processables,prohibitives and the marketable recyclables removed from the wastestream, the waste stream can be conveyed to the primary shredder 230. Insome embodiments, the primary shredder 230 can further be configured toreceive recycling residue, as shown by the arrow BB in FIG. 2. Forexample, in some embodiments, the primary shredder 230 can receive thewaste stream conveyed from the tipping floor F and recycling residuedelivered from, for example, a material recovery facility.

The primary shredder 230 can be any suitable shredder configured toreduce the size of the constituents of the waste stream to a suitablesize. For example, in some embodiments, the constituents of the wastestream can be reduced to a size less than about 10-12 inches. In otherembodiments, the shredder can be configured to reduce the size of theconstituents of the waste stream to be less than 4 inches, and in stillother embodiments the shredder can be configured to reduce the size ofthe constituents of the waste stream to be between about 0.75 inches andabout 1 inch.

The system 200 can further include a conveyer configured to transfer aportion of the waste stream from the primary shredder 230 to the densityseparator 243. The conveying of the material can be pneumatically (viaair blower) or mechanically (e.g. screw conveyor). The density separator243 can be configured such that a first set of constituents of the wastestream with a density below a predetermined density threshold (e.g.,plastics and/or fibers) pass through the density separator 243 to thesecondary shredder 235. A second set of constituents of the waste streamwith a density above the predetermined density threshold (e.g., ferrousmetals, non-ferrous metals, glass, dirt, and/or the like) are configuredto pass through the density separator 243 to additional separationsprocesses. For example, the metals, glass, dirt, etc. can be conveyed tothe magnetic separator 244 where the marketable ferrous metals (e.g.,steel) are recovered. The remaining metals, glass, dirt, etc. can beconveyed to the eddy current separator 245 where the marketablenon-ferrous metals (e.g., aluminum) are recovered. The residualnon-metallic material can then optionally be conveyed to the glassseparator 246 to remove the glass particles. In some embodiments, theglass separator 246 is an optical glass separator. In other embodiments,the glass separator 246 can be any suitable separator. With the portionof the waste stream substantially free of metals and/or glass, theremaining constituents (e.g., residues) can be disposed of in, forexample, a landfill, if no other beneficial use of the material can beidentified. In some embodiments where recycled glass does not have amarket value, the glass separator can be omitted and/or bypassed and theglass can be disposed of with the residues at a landfill, or used asdaily cover material in landfill.

As described above, the first set of constituents of the waste stream(e.g., the plastics and fibers with a density below the densitythreshold of the density separator 243) are conveyed to the secondaryshredder 235. The secondary shredder 235 can be any suitable shredder.For example, in some embodiments, the secondary shredder 235 issubstantially similar to the primary shredder 230. In other embodiments,the secondary shredder 235 is different from the primary shredder 235.Furthermore, the secondary shredder 235 can be configured to shred theconstituents of the waste stream to any suitable size, e.g. a smallersize than produced by the primary shredder 235. For example, in someembodiments, the secondary shredder is configured to shred theconstituents to a size between about 0.375 (⅜″) inches and about 0.25(¼″) inches. In other embodiments, the secondary shredder 235 can shredthe constituents of the waste stream to a size less than or equal toabout 0.09375 ( 3/32″) inches.

In some embodiments, the density separator 243 can be configured toinclude multiple stages and/or portions. For example, in someembodiments, the waste stream can be delivered to a screen included inthe density separator 243. In such embodiments, the screen can define apredetermined mesh size and can be configured to separate the wastestream into a first portion including a constituent size of less thanthe mesh size and a second portion including a constituent size greaterthan mesh size. In some embodiments, the first portion of the wastestream can be delivered to a first density separator (not shown) and thesecond portion of the waste stream can be delivered to a second densityseparator (not shown). In some embodiments, for example, the screen candefine a mesh size of about 0.25 inches. In some embodiments, theseparation of the waste stream into the first portion, having the firstconstituent size, and the second portion, having the second constituentsize, can increase the efficiency of the first density separator and/orthe second separator. In such embodiments, constituents of greater sizecan, for example, reduce the efficiency of the first separator, causethe first separator to malfunction, and/or cause the first separatorinadequately separate the constituents. With the constituents separatedby the first density separator or the second density separator, theconstituents with a density greater than the density threshold (e.g.,ferrous metals, non-ferrous metals, glass, dirt, and/or the like) areconveyed to the set of separators, as described above. Furthermore, theconstituents of the waste stream with a density below the densitythreshold of the first density separator and/or the second densityseparator (e.g., the plastics and fibers) can be conveyed to thesecondary shredder 235.

In some embodiments, the waste stream can be conveyed from the secondaryshredder 235 to an additional density separator configured to separatethe constituents of the waste stream, as described above. In suchembodiments, the additional density separator can be used to ensure thewaste stream is substantially free from metals, glass, and/or any othermaterial that can, for example, have adverse effects on the materialclassification subsystem 220. With the size of the constituents of thewaste stream reduced to a predetermined size and the waste streamsufficiently separated, the waste stream can be transferred to thematerial classification subsystem 220.

The material classification subsystem 220 can be any suitable systemconfigured to further separate (e.g., classify) a desired set ofmaterial. For example, in some embodiments, the material classificationsubsystem 220 receives the portion of the waste stream having a densitybelow the density threshold of the density separator 243 (e.g., plasticsand fibers). In such embodiments, the material classification subsystem220 can separate the incoming material into, for example, hard plastic,soft plastic, and/or fiber via any suitable method. In some embodiments,the material classification subsystem 220 can include cyclonicseparators, fluidized beds, density separators, and/or the like. In thismanner, the material classification subsystem 220 can separate the wastestream and store the separated constituents in, for example, bunkers(not shown in FIG. 2).

The system 200 can further include a delivery mechanism (e.g., aconveyer) to convey the hard plastic, the soft plastic, and/or the fiberto the fuel feed stock production subsystem 280. The EF subsystem 280can be any suitable system. For example, in some embodiments, the EFsubsystem 280 can include a portion configured to deliver additives tothe waste stream (e.g., chemical additives, sorbents, biomass,biomaterials, and/or the like), a milling portion, an extrusion portion,and/or any other suitable portion.

Expanding further, in some embodiments, the portion of the waste stream(e.g., the hard plastic, soft plastic, and/or fiber) can be mixed withthe additives and compressed to form, for example, a densifiedintermediate material, as described above. In this manner, theconstituents of the separated waste stream (e.g., the constituents ofthe waste stream conveyed from the material classification subsystem220) can be combined with additives and/or portions of processedmaterials and processed to produce an engineered fuel feed stock, asdescribed in further detail herein.

While the primary shredder 230 described with respect to FIG. 2 is shownreceiving both municipal solid waste and recycling residue, in someembodiments, a primary shredder can be configured to receive onlyrecycling residue. For example, as shown in FIG. 3, a system 300includes at least a primary shredder 330, a material classificationsubsystem 320, and a set of conveyers C. The primary shredder 330 can beany suitable shredder or shredders. For example, in some embodiments,the primary shredder 330 can be substantially similar to the primaryshredder 230 described above with respect to FIG. 2. In someembodiments, the material classification subsystem 320 can furtherinclude a secondary shredder 335, a set of cyclonic separators 341, aset of bunkers 360, a dust filter 352, and a blower 370. The set ofcyclonic separators 341 can be any suitable cyclonic separators. Forexample, the cyclonic separators 341 can be configured such that a gas(e.g., air) flows within the cyclonic separator 341 in a helical manner.The cyclonic separators 341 can further be configured such that the flowrate of the air, within the cyclonic separators, separates materialsbased on a predetermined density threshold, as described in furtherdetail herein.

The primary shredder 330 can be configured to receive recycling residue,as shown by the arrow CC in FIG. 3. With the system 300 receivingrecycling residue, the use of multiple separation devices for removingundesired materials from the waste stream (e.g., a magnetic separator,an eddy current separator, and/or a glass separator) can be reduced tousing the material classification subsystem 320, as shown in FIG. 3.Similarly stated, since the waste stream is substantially limited torecycling residue, the need for certain separators (e.g., the magneticseparator, the eddy current separator, and/or the glass separator) isreduced or eliminated because the waste stream includes a limited amountof constituents separated by those separators. Said yet another way, thewaste stream of the system 300 is sufficiently free fromnon-processables (e.g., metals, glass, dirt, and/or the like) that thematerial classification subsystem 320 can be employed to substantiallyremove the undesirable material and/or classify the waste stream.

In this manner, a first conveyer C can be configured to convey theshredded material (e.g., the waste stream shredded to a size of about0.375 inches) to the material classification subsystem 320. Morespecifically, the first conveyer C can be configured to convey theshredded material to a first cyclonic separator 341A to remove, forexample, glass, metal, and/or dirt fines. Expanding further, the firstcyclonic separator 341A can define a flow rate such that a portion ofthe waste stream (e.g., glass, metals, and/or dirt fines) issufficiently dense to fall through the first cyclonic separator 341A andinto a first bunker 360A. Conversely, a second portion of the wastestream (e.g., plastics and/or fibers) has a sufficiently lower densitysuch that it is entrained in the air flow of the first cyclonicseparator 341A. In this manner, the second portion of the waste streamis transferred from the first cyclonic separator 341A to the secondaryshredder 335.

The secondary shredder 335 can be configured to shred the constituentsof the waste stream to any suitable size, as described above. With thesize of the constituents of the waste stream reduced, the waste streamcan be delivered via a second conveyer C to a second cyclonic separator341B. The second cyclonic separator 341B can be substantially similar inform and function to the first cyclonic separator 341A. However, in someembodiments, the flow rate of the second cyclonic separator 341B can besuch that the second cyclonic separator 341B is configured to separatehard plastic material from the waste stream. Similarly stated, in someembodiments, hard plastics in the waste stream have a density that issufficiently higher than the other components of the waste stream sothat the hard plastics fall to the bottom of the second cyclonicseparator 341B and are stored in a second bunker 360B. Furthermore, theportion of the waste stream (e.g., soft plastics and/or fibers) having alower density remains entrained in the air flow of the second cyclonicseparator 341B and is transferred from the second cyclonic separator341B to a third cyclonic separator 341C.

The third cyclonic separator 341C can be substantially similar in formand function to the first cyclonic separator 341A and/or the secondcyclonic separator 341B. However, in some embodiments, the flow rate ofthe third cyclonic separator 341C can be such that the third cyclonicseparator 341C is configured to separate fibers (e.g., papers and/or thelike) from the waste stream. Similarly stated, in some embodiments,fibers in the waste stream have a density that is sufficiently higherthan the other components of the waste stream so that the fibers fall tothe bottom of the third cyclonic separator 341C and are stored in athird bunker 360C. Furthermore, the portion of the waste stream (e.g.,soft plastics) having a lower density remains entrained in the air flowof the third cyclonic separator 341C and is transferred from the thirdcyclonic separator 341C to a fourth cyclonic separator 341D.

The fourth cyclonic separator 341D can be substantially similar in formand function to the cyclonic separators 341A, 341B, and/or 341C.However, in some embodiments, the flow rate of the fourth cyclonicseparator 341D can be such that soft plastics are separated from thewaste stream. Similarly stated, in some embodiments, soft plastics inthe waste stream have a density that is sufficiently higher than theother components of the waste stream so that the soft plastics fall tothe bottom of the fourth cyclonic separator 341D and are stored in afourth bunker 360D. Furthermore, the portion of the waste stream (e.g.,dust particles) having a lower density remains entrained in the air flowof the fourth cyclonic separator 341D and is transferred from the fourthcyclonic separator 341D to the dust filter 352, configured tosubstantially remove dust particles from the air. With the airsubstantially free of dust, the air can be delivered to the blower 370.In some embodiments, the blower 370 is configured to feed a portion ofthe air to the first, second, third, and/or fourth cyclonic separator341A, 341B, 341C, 341D, respectively. In other embodiments, the blower370 can be configured to vent the air, for example, to the atmosphere.

While the material classification subsystem 320 is described asincluding cyclonic separators 341, in some embodiments, a materialclassification subsystem can include any suitable separator and/orcombination of separators. For example, as shown in FIG. 4, a materialclassification subsystem 420 includes a cyclonic separator 441 and afluidized bed separator 447. Expanding further, the materialclassification subsystem 420 includes a granulator 432 configured toreceive a waste stream, as shown by the arrow DD. In some embodiments,the waste stream can be recycling residue. In other embodiments, thewaste stream can be a portion of a municipal solid waste stream (e.g.,MSW substantially free from metals, glass, and/or any othernon-processables or marketable recyclables).

The granulator 432 can be configured to reduce the size of theconstituents of the waste stream. In some embodiments, the granulator432 is configured to shred the constituents of the waste stream to asize between about 0.375 inches and about 0.25 inches. In otherembodiments, the granulator 432 can shred the constituents of the wastestream to a size less than or equal to about 0.09375 inches. With thesize of the constituents of the waste stream reduced, the shredded wastestream can be delivered to the cyclonic separator 441. Morespecifically, the material classification subsystem 420 can include ablower 470 configured to transport the shredded waste stream from thegranulator 432 to the cyclonic separator 441. In some embodiments, thewaste stream can be conveyed through a tube, shaft, a channel, a pipe, aduct, or the like.

In some embodiments, the cyclonic separator 441 can be substantiallysimilar in form and function as the cyclonic separators 341 describedabove with respect to FIG. 3. In some embodiments, the cyclonicseparator 441 can define a flow rate such that a portion of the wastestream (e.g., dirt, hard plastic, fiber, and soft plastic) issufficiently dense to pass through the cyclonic separator 441 to aconveyer C. Said another way, the flow rate of the cyclonic separator441 can be such that fine particles (e.g., dust and/or powders) of thewaste stream have a sufficiently low density to remain entrained in theair flow of the cyclonic separator 441. In other embodiments, thecyclonic separator 441 can be configured to remove or separate anysuitable constituent from the waste stream.

As described above, portions of the waste stream can pass through thecyclonic separator 441 to the conveyer C. The portions of the wastestream include, for example, dirt, hard plastic, fiber, and softplastic. The conveyer C receives the portion of the waste stream and isconfigured to deliver the portion of the waste stream to the fluidizedbed 447, as shown in FIG. 4. The fluidized bed 447 includes a firstchamber 448, a second chamber, 449, a third chamber 450, and a fourthchamber 451. In some embodiments, the fluidized bed 447 can beconfigured to separate portions of the waste stream via a separationfluid (e.g., air). Expanding further, the fluidized bed 447 can includea predetermined flow rate and/or flow volume to separate theconstituents of the waste stream based on density. Similarly stated,with the constituents of the waste stream reduced (e.g., by thegranulator 432) to a substantially uniform size, the separation of thewaste stream into a first portion entrained in the air flow of thefluidized bed 447 and a second portion not entrained in the air flow ofthe fluidized bed 447 can be based on the density of the constituents.In some embodiments, the feed rate of the constituents into thefluidized bed 447 and/or the flow rate of the air can be controlledwithin a predetermined range such that the fluidized bed 447 canseparate the constituents at or about a predetermined density. Thus, thefirst portion of the waste stream (i.e., the portion entrained in theair flow of the fluidized bed 447) has a density less than thepredetermined density and will float to the top of the fluidized bed447. The second portion (i.e., the portion not entrained in the air flowof the fluidized bed 447) has a density greater than predetermineddensity and will sink to the bottom of the fluidized bed 447. In thismanner, the first chamber 448, the second chamber 449, the third chamber450, and the fourth chamber 451 of the fluidized bed 447 can beconfigured to separate the constituents of the waste stream at or abouta first predetermined density, a second predetermined density, a thirdpredetermined density, and a fourth predetermined density, respectively.

As shown in FIG. 4, the first chamber 448 of the fluidized bed 447 canbe configured to separate dirt from the waste stream. In suchembodiments, the first chamber 448 can be configured to separate theconstituents of the waste stream at a predetermined separation densityrange between, for example, between about 25-75 pounds per cubic foot.Therefore, the dirt in the waste stream (e.g., with density betweenabout 75-120 pounds per cubic foot) is sufficiently dense to sinkrelative to the other constituents of the waste stream and fall to thebottom of the first chamber 448. Furthermore, a first storage bunker460A can be coupled to the first chamber 448 of the fluidized bed 447such that the as dirt sinks to the bottom of the first chamber 448, thedirt is stored in the first bunker 460A.

As described above, a portion of the waste stream (e.g., hard plastic,fiber, and/or soft plastic) with a density below the predeterminedseparation density range of the first chamber 448 of the fluidized bed447 is configured to float relative to other portions within the firstchamber 448. Thus, the arrangement of the fluidized bed 447 can be suchthat the constituents are transferred to the second chamber 449 of thefluidized bed 447, as shown by the arrow EE in FIG. 4. The secondchamber 449 can be configured to separate the constituents of the wastestream at a predetermined separation density range between, for example,the density of the hard plastics and the density of the fibers (e.g.,6-18 pounds per cubic foot). In this manner, the hard plastics in thewaste stream (e.g., with density of about 20 pounds per cubic foot) aresufficiently dense to sink relative to the other constituents of thewaste stream and fall to the bottom of the second chamber 449.Furthermore, a second storage bunker 460B can be coupled to the secondchamber 449 of the fluidized bed 447 such that as the hard plastic sinksto the bottom of the second chamber 449, the hard plastic is stored inthe second bunker 460B.

A portion of the waste stream (e.g., fiber and/or soft plastic) with adensity below the predetermined separation density range of the secondchamber 449 of the fluidized bed 447 is configured to float relative tothe other portions within the second chamber 449. Thus, the arrangementof the fluidized bed 447 can be such that the constituents aretransferred to the third chamber 450 of the fluidized bed 447, as shownby the arrow FF in FIG. 4. The third chamber 450 can be configured toseparate the constituents of the waste stream at a predeterminedseparation density range between, for example, the density of the fibersand the density of the soft plastics (e.g., about 3 pounds per cubicfoot). In this manner, the fibers in the waste stream (e.g., withdensity of about 4 pounds per cubic foot) are sufficiently dense to sinkrelative to the other constituents of the waste stream and fall to thebottom of the third chamber 450. Furthermore, a third storage bunker460C can be coupled to the third chamber 450 of the fluidized bed 447such that as the fiber sinks to the bottom of the third chamber 450, thefiber is stored in the third bunker 460C.

A portion of the waste stream (e.g., soft plastic) with a density belowthe predetermined separation density range of the third chamber 450 ofthe fluidized bed 447 is configured to float relative to the otherportions within the third chamber 450. Thus, the arrangement of thefluidized bed 447 can be such that the constituents are transferred tothe fourth chamber 451 of the fluidized bed 447, as shown by the arrowGG in FIG. 4. The fourth chamber 451 can be configured to separate theconstituents of the waste stream at a predetermined separation densityrange below, for example, the density of the soft plastics (e.g., lessthan 2 pounds per cubic foot). In this manner, the soft plastics in thewaste stream (e.g., with density of about 2 pounds per cubic foot) aresufficiently dense to sink relative to the other constituents of thewaste stream and fall to the bottom of the fourth chamber 451.Furthermore, a fourth storage bunker 460D can be coupled to the fourthchamber 451 of the fluidized bed 447 such that as the soft plastic sinksto the bottom of the fourth chamber 451, the soft plastic is stored inthe fourth bunker 460D. The fluidized bed 447 can be further configuredto vent excess air to stabilize the pressure within the fluidized bed447. In some embodiments, the air can be circulated back to the blowers470. In other embodiments, the air is vented to the atmosphere.

In some embodiments, the dirt stored in the first bunker 460A isconveyed to a disposal system. The disposal system can be, for example,transporting the dirt to a landfill. In other embodiments, the dirt canbe processed (e.g., cleaned) and sold. In some embodiments, the hardplastic stored in the second bunker 460B, the fiber stored in the thirdbunker 460C, and the soft plastic stored in the fourth bunker 460D aredelivered to a fuel feed stock production system, such as, for example,those described herein. Engineered fuel feed stocks are described inU.S. Pat. Nos. 8,157,874 and 8,157,875 to Bohlig et al., filed Apr. 14,2011, entitled “Engineered Fuel Feed Stock,” the disclosures of whichare hereby incorporated herein by reference, in their entireties.

Referring now to FIG. 5, in some embodiments, a material classificationsubsystem 520 includes a first, second, third, and fourth cyclonicseparator (541A, 541B, 541C, and 541D, respectively) and a first,second, and third, fluidized bed separator (547A, 547B, 547C,respectively). The material classification subsystem 520 furtherincludes a granulator 532 configured to receive a waste stream, as shownby the arrow HH. In some embodiments, the waste stream can be recyclingresidue. In other embodiments, the waste stream can be a portion of amunicipal solid waste stream (e.g., MSW substantially free from metals,glass, and/or any other undesired material).

The granulator 532 can be configured to reduce the size of theconstituents of the waste stream, as described above with respect toFIG. 4. With the size of the constituents of the waste stream reduced,the shredded waste stream can be delivered to the first cyclonicseparator 541A. More specifically, the material classification subsystem520 can include a blower 570 configured to transport the shredded wastestream from the granulator 532 to the first cyclonic separator 541A. Insome embodiments, the waste stream can be conveyed through a tube,shaft, a channel, a pipe, or the like.

In some embodiments, the first cyclonic separator 541A can besubstantially similar in form and function as the cyclonic separators441 described above with respect to FIG. 4. In some embodiments, thefirst cyclonic separator 541A can define a flow rate such that a portionof the waste stream (e.g., dirt, hard plastic, fiber, and soft plastic)is sufficiently dense to fall through the first cyclonic separator 541Ato a conveyer C. Said another way, the flow rate of the first cyclonicseparator 541A can be such that fine particles (e.g., dust and/orpowders) of the waste stream have a sufficiently low density to remainentrained in the air flow of the first cyclonic separator 541A. In otherembodiments, the first cyclonic separator 541A can be configured toremove or separate any suitable constituent from the waste stream.

As described above with respect to FIG. 4, portions of the waste streampass through the first cyclonic separator 541A to the conveyer C. Insome embodiments, the portion of the waste stream can include dirt witha density between about 75-120 pounds per cubic foot, hard plastics witha density of about 20 pounds per cubic foot, fibers with a density ofabout 4 pounds per cubic foot, and soft plastics with a density of about2 pounds per cubic foot. The conveyer C receives the portion of thewaste stream and is configured to deliver the portion of the wastestream to the first fluidized bed 547A, as shown in FIG. 5. Thefluidized beds 547, as described herein, can be substantially similar infunction to the fluidized bed 447 described with respect to FIG. 4.Therefore, functional details of the fluidized beds 547 are notdescribed in further detail.

The first fluidized bed 547A can be configured to separate the softplastics (and constituents with densities less than that of softplastics such as, for example, dust or powders) from the waste stream.In such embodiments, the first fluidized bed 547A can be configured toseparate the constituents of the waste stream at a predeterminedseparation density range between, for example, the density of the fibersand the density of the soft plastics (e.g., about 3 pounds per cubicfoot). In this manner, the soft plastics (e.g., with density of about 2pounds per cubic foot) are not sufficiently dense to sink relative tothe first fluidized bed 547A. Thus, the soft plastics (and any otherconstituent with a density less the density of soft plastics) float orentrain relative to the other constituents within the first fluidizedbed 547A and are transported to a second cyclonic separator 541B. Thesecond cyclonic separator 541B can include a flow rate defining adensity threshold configured to separate the soft plastic from the otherconstituents. Similarly stated, the soft plastic is sufficiently denseto fall to the bottom of the second cyclonic separator 541B and into afirst storage bunker 560A. Furthermore, constituents with a density lessthan the density threshold are entrained in the air flow and can besuitably disposed of.

Referring back to the first fluidized bed 547A, the constituents withdensities greater than the predetermined density range of the firstfluidized bed 547A sink to the bottom of the first fluidized bed 547Aand are delivered to a conveyer C. The conveyer C is configured todeliver the constituents of the waste stream to the second fluidized bed547B. The second fluidized bed 547B can be configured to separate theconstituents of the waste stream at a predetermined separation densityrange between, for example, about 25-70 pounds per cubic foot.Therefore, the dirt (e.g., with density between about 75-120 pounds percubic foot) is sufficiently dense to sink relative to the otherconstituents of the waste stream and fall to the bottom of the secondfluidized bed 547B. Furthermore, a second storage bunker 560B can becoupled to the second fluidized bed 547B such that as the dirt sinks tothe bottom of the second fluidized bed 547B, the dirt is stored in thesecond bunker 560B.

A portion of the waste stream with a density below the predetermineddensity range of the second fluidized bed 547B is configured to floatrelative to the other portions of the second fluidized bed 547B. Thus,the arrangement of the second fluidized bed 547B can be such that theconstituents are transferred to the third cyclonic separator 541C. Thethird cyclonic separator 541C can include a flow rate defining a densitythreshold configured to separate the hard plastics and the fiber fromthe other constituents. Similarly stated, the hard plastics and thefibers are sufficiently dense to fall to the bottom of the thirdcyclonic separator and are delivered to a conveyer C.

The third fluidized bed 547C can be configured to separate theconstituents of the waste stream at a predetermined separation densityrange between, for example, the density of the hard plastics and thedensity of the fibers (e.g., about 6-18 pounds per cubic foot. In thismanner, the hard plastics (e.g., with density of about 20 pounds percubic foot) are sufficiently dense to sink relative to the otherconstituents of the waste stream and fall to the bottom of the thirdfluidized bed 547C. Furthermore, a third storage bunker 560C can becoupled to the third fluidized bed 547C such that as the hard plasticssink to the bottom of the third fluidized bed 547C, the hard plasticsare stored in the third bunker 560C.

A portion of the waste stream with a density below the predetermineddensity range of the third fluidized bed 547C is configured to floatrelative to the other portions of the third fluidized bed 547C. Thus,the arrangement of the third fluidized bed 547C can be such that theconstituents are transferred to the fourth cyclonic separator 541D. Thefourth cyclonic separator 541D can include a flow rate defining adensity threshold configured to separate the fibers (e.g., with densityof about 4 pounds per cubic foot) from the other constituents. Similarlystated, the fibers are sufficiently dense to fall to the bottom of thefourth cyclonic separator and into a fourth storage bunker 560D.Furthermore, constituents with a density less than the density thresholdare entrained in the air flow and can be suitably disposed of.

In some embodiments, the dirt stored in the second bunker 560B istransferred to a disposal system. The disposal system can be, forexample, transporting the dirt to a landfill. In other embodiments, thedirt can be processed (e.g., cleaned) and sold. In some embodiments, thesoft plastics stored in the first bunker 560A, the hard plastics storedin the third bunker 560C, and the fibers stored in the fourth bunker560D are delivered to a fuel feed stock production system, such as, forexample, those described herein. In some embodiments, the passage of thewaste stream through cyclonic separators 541 before entering thefluidized beds 547 can result in cleaner constituents stored in thebunkers 560.

Referring now to FIG. 6, in some embodiments, a material classificationsubsystem 620 includes a first and second cyclonic separator (641A,641B, respectively) and a first and second fluidized bed separator(647A, 647B, respectively). The material classification subsystem 620further includes a granulator 632 configured to receive a waste stream,as shown by the arrow II. In some embodiments, the waste stream can berecycling residue. In other embodiments, the waste stream can be aportion of a municipal solid waste stream (e.g., MSW substantially freefrom metals, glass, and/or any other undesired material).

The granulator 632 can be configured to reduce the size of theconstituents of the waste stream, as described above with respect toFIGS. 4 and 5. With the size of the constituents of the waste streamreduced, the shredded waste stream can be delivered to the firstcyclonic separator 641A. More specifically, the material classificationsubsystem 620 can include a blower 670 configured to transport theshredded waste stream from the granulator 632 to the first cyclonicseparator 641A. In some embodiments, the waste stream can be conveyedthrough a tube, shaft, a channel, a pipe, or the like.

In some embodiments, the first cyclonic separator 641A can besubstantially similar in form and function as the first cyclonicseparator 541A described above with respect to FIG. 5. In someembodiments, the first cyclonic separator 641A can define a flow ratesuch that a portion of the waste stream (e.g., dirt, hard plastic,fiber, and soft plastic) is sufficiently dense to pass through the firstcyclonic separator (e.g., fall to the bottom of the first cyclonicseparator 641A) to a conveyer C. Said another way, the flow rate of thefirst cyclonic separator 641A can be such that fine particles (e.g.,dust and/or powders) of the waste stream have a sufficiently low densityto remain entrained in the air flow of the first cyclonic separator641A. In other embodiments, the first cyclonic separator 641A can beconfigured to remove or separate any suitable constituent from the wastestream.

The portions of the waste stream that pass through the first cyclonicseparator 641A can be delivered to the conveyer C. In some embodiments,the portion of the waste stream can include dirt with a density betweenabout 75-120 pounds per cubic foot, hard plastics with a density ofabout 20 pounds per cubic foot, fibers with a density of about 4 poundsper cubic foot, and soft plastics with a density of about 2 pounds percubic foot. The conveyer C receives the portion of the waste stream andis configured to deliver the portion of the waste stream to the firstfluidized bed 647A, as shown in FIG. 6. The fluidized beds 647, asdescribed herein, can be substantially similar in function to thefluidized bed 447 described with respect to FIG. 4. Therefore,functional details of the fluidized beds 647 are not described infurther detail.

The first fluidized bed 647A can be configured to separate the softplastics (and constituents with densities less than that of softplastics such as, for example, dust or powders) from the waste stream.In such embodiments, the first fluidized bed 647A can be configured toseparate the constituents of the waste stream at a predeterminedseparation density range between, for example, the density of the fibersand the density of the soft plastics (e.g., about 3 pounds per cubicfoot). In this manner, the soft plastics (e.g., with density of about 2pounds per cubic foot) are not sufficiently dense to sink relative tothe first fluidized bed 647A. Thus, the soft plastics (and any otherconstituent with a density less the density of soft plastics) floatrelative to the other constituents within the first fluidized bed 647Aand are transported to a second cyclonic separator 641B. The secondcyclonic separator 641B can include a flow rate defining a densitythreshold configured to separate the soft plastic from the otherconstituents. Similarly stated, the soft plastic is sufficiently denseto fall to the bottom of the second cyclonic separator 641B and into afirst storage bunker 660A. Furthermore, constituents with a density lessthan the density threshold are entrained in the air flow and can besuitably disposed of.

Referring back to the first fluidized bed 647A, the constituents withdensities greater than the predetermined separation density of the firstfluidized bed 647A sink to the bottom of the first fluidized bed 647Aand are delivered to a conveyer C. The conveyer C is configured todeliver the constituents of the waste stream to the second fluidized bed647B. As shown in FIG. 6, the second fluidized bed 647B include a firstchamber 648, a second chamber 649, and a third chamber 650. The firstchamber 648 can be configured to separate the constituents of the wastestream at a predetermined separation density range between, for example,about 25-70 pounds per cubic foot. Therefore, the dirt (e.g., withdensity between about 75-120 pounds per cubic foot) is sufficientlydense to sink relative to the other constituents of the waste stream andfall to the bottom of the first chamber 648. Furthermore, a secondstorage bunker 660B can be coupled to the first chamber 648 of thefluidized bed 647 such that as the dirt sinks through the first chamber648, the dirt is stored in the second bunker 660B.

A portion of the waste stream with a density below the predetermineddensity range of the first chamber 648 of the fluidized bed 647 isconfigured float relative to the other portions of the waste streamwithin the first chamber 648. Thus, the arrangement of the fluidized bed647 can be such that the constituents are transferred to the secondchamber 649 of the fluidized bed 647, as shown by the arrow JJ in FIG.6. The second chamber 649 can be configured to separate the constituentsof the waste stream at a predetermined separation density range between,for example, the density of the hard plastics and the density of thefibers (e.g., about 6-18 pounds per cubic foot). In this manner, thehard plastic (e.g., with density of about 20 pounds per cubic foot) issufficiently dense to sink relative to the other constituents of thewaste stream and fall to the bottom of the second chamber 649 of thefluidized bed 647. Furthermore, a third storage bunker 660C can becoupled to the second chamber 649 such that as the hard plastic sinksthrough the second chamber 649, the hard plastics are stored in thethird bunker 660C.

A portion of the waste stream with a density below the predetermineddensity range of the second chamber 649 of the fluidized bed 647 isconfigured to float relative to the other portions of the waste streamwithin the second chamber 648. Thus, the arrangement of the fluidizedbed 647 can be such that the constituents are transferred to the thirdchamber 650 of the fluidized bed 647, as shown by the arrow KK. Thethird chamber 650 can be configured to separate the constituents of thewaste stream at a predetermined separation density range between, forexample, the density of the fibers and the density of the soft plastics(e.g., about 3 pounds per cubic foot). In this manner, the fibers (e.g.,with density of about 4 pounds per cubic foot) are sufficiently dense tosink relative to the other constituents of the waste stream and fall tothe bottom of the third chamber 650 of the fluidized bed 647.Furthermore, a fourth storage bunker 660D can be coupled to the thirdchamber 650 of the fluidized bed 647 such that as the fibers sinkthrough the third chamber 650, the fibers are stored in the fourthbunker 660D.

FIG. 7 is a schematic illustration of a system 700 for producing anengineered fuel feed stock from solid waste material. The system 700includes at least a separation subsystem 715 and a fuel feed stockproduction subsystem 780 (also referred to herein as “engineered fuelsubsystem 780” or “EF subsystem 780” or “Advanced Product Manufacturing(APM) subsystem 780”). In some embodiments, a waste stream can betransferred to the separation subsystem 715, as shown by arrow LL inFIG. 7. The waste stream can be, for example, MSW delivered via acollection truck or recycling residue from a recycling facility. Inother embodiments, the solid waste can be delivered via a conveyer froma material recovery facility or other waste handling facility. Theseparation subsystem 715 can be configured to separate the waste streamthat non-processables and/or marketable recyclables are removed (e.g.,separated) from the waste stream. Expanding further, the separationsubsystem 715 can be any of the systems described with reference toFIGS. 2-6 or any combination thereof. In some embodiments, theseparation subsystem 715 can include any number of separators (e.g.,magnetic separators, eddy current separators, glass separators,fluidized bed separators, cyclonic separators, and/or the like),shredders and granulators. In this manner, the separation subsystem 715can receive a waste stream (e.g., MSW and/or recycling residue) andtransfer separated constituents of the waste stream into bunkers 760.For example, in some embodiments, the material classification subsystem720 can include a first bunker configured to store hard plastics, asecond bunker configured to store soft plastics, and a third bunkerconfigured to store fibers. In this manner, the system 700 can furtherinclude a delivery mechanism (e.g., a conveyers, tubes, pipes, channels,and/or the like) to convey the hard plastics, the soft plastics, and/orthe fibers to the EF subsystem 780.

The EF subsystem 780 can be any suitable system suitable for combiningthe classified waste materials with additives in predetermined ratios toproduce an engineered fuel feed stock. The EF subsystem 780 can include,for example, a portion configured to deliver additives to the wastestream (e.g., chemical additives, sorbents, biomass, biomaterials,and/or the like), conditioners, mixers, conveyers, densifiers,granulators, pulverizers, storage bunkers, and/or any other suitabledevices or systems.

In some embodiments, at least a portion of the waste stream can bedelivered to the EF subsystem 780 to produce an engineered fuel feedstock. Expanding further, in some embodiments, the materialclassification subsystem 715 can be configured to deliver a givenquantity of the hard plastics to the EF subsystem 780. In suchembodiments, the hard plastics can be passed through a pre-treatmentmechanism 756. The pre-treatment mechanism 756 can be, for example, aheater configured to raise the temperature of the hard plastics. In someembodiments, the pretreatment mechanism can receive at least a portionof the sorbent 790. In still other embodiments, the soft plastic portiondelivered to the mixer 754A can be first directed to the pretreatmentmechanism 756. The EF subsystem 780 can further include a set of mixers754 configured to receive at least a portion of the waste streamdelivered by the material classification subsystem 720 and meteringdevices 775 configured to control the flow of the waste stream into themixers 754.

The mixers 754 can be any suitable device such as paddled continuousmixer, rotary continuous mixer, screw conveyor or auger conveyor mixer,mechanically vibrating or agitating mixer. In some embodiments, thematerial classification subsystem 715 can deliver a first waste streamincluding hard plastics and a second waste stream including softplastics to a first mixer 754A. In such embodiments, the first mixer754A is configured to mix a metered amount of the hard plastics with ametered amount of the soft plastics. In this manner, the first mixer754A can deliver the mixed waste stream to a blower 770 configured tofeed the waste stream to a first conditioner 755A. In other embodiments,the hard plastics can be configured to pass through the first mixer 754Aand remain substantially unmixed (e.g., the metering mechanism 775 doesnot supply a quantity of the soft plastics). In this manner, a wastestream including substantially only hard plastics can be delivered tothe first conditioner 755A, as further described herein.

The first conditioner 755A can be any suitable device and/or systemconfigured to condition at least a portion of the waste stream forengineered fuel feed stock production. For example, in some embodiments,the first conditioner 755A can be configured to increase the temperatureof the constituents of the waste stream (e.g., the hard plastics). Insome embodiments, the first conditioner 755A can be configured toincrease the moisture of the constituents of the waste stream. In someembodiments, the first conditioner 755A can receive the portion of thewaste stream and a set of additives. In some embodiments, the additivescan be chemical additives (e.g., sorbents, nutrients, promoters, and/orthe like), biomass waste (e.g., wood), biomaterials (e.g., animalmanure), and/or any other suitable additive or additives, in solids orsolution form (e.g. urea, acetic acid, mercury oxidizing agents such ascalcium bromide, ammonium bromide, sodium bromide, etc., for mercuryreduction). For example, in some embodiments, the first conditioner 755Acan be configured to receive a sorbent 790. In such embodiments, thesorbent 790 can be configured to alter the combustion properties of theconstituents of the waste stream. For example, in some embodiments, thesorbent 790 can be configured to absorb sulfur dioxide (SO₂). In otherembodiments, the sorbent 790 can be configured to absorb and/orneutralize odors, burn with a given color, and/or the like. In someembodiments, the sorbent 790 can be conditioned by a second conditioner755B prior to being delivered to the first conditioner 755A. In suchembodiments, the second conditioner 755B can be configured to, forexample, raise the temperature of the sorbent 790. Examples of additivesthat can be incorporated into the engineered fuel feed stock using thesubsystem 780 include sodium sesquicarbonate (Trona), sodiumbicarbonate, sodium carbonate, zinc ferrite, zinc copper ferrite, zinctitanate, copper ferrite aluminate, copper aluminate, copper managaneseoxide, nickel supported on alumina, zinc oxide, iron oxide, copper,copper (I) oxide, copper (II) oxide, limestone, lime, Fe, FeO, Fe₂O₃,Fe₃O₄, iron filings, CaCO₃, Ca(OH)₂, CaCO₃.MgO, silica, alumina, chinaclay, kaolinite, bauxite, emathlite, attapulgite, coal ash, egg shells,organic salts (such as calcium magnesium acetate (CMA), calcium acetate(CA), calcium formate (CF), calcium benzoate (CB), calcium propionate(CP) and magnesium acetate (MA)) and Ca-montmorillonite.

The first conditioner 755A can further be configured to deliver theconditioned waste stream and additives to a first densifier 731A. Thefirst densifier 731A can be any suitable device configured toencapsulate at least a portion of the sorbent 790 within the plastics.For example, in some embodiments, the first densifier 731A can be anextrusion device configured to apply a relatively high pressure (e.g.,compress) to the plastics and the sorbent 790 such that the sorbent 790becomes evenly distributed (e.g., substantially homogenous) and/orencapsulated within the plastics. Furthermore, the first densifier 731Acan be configured to produce a densified intermediate material. Thedensified intermediate material can be in the form of cubes, briquettes,pellets, honeycomb, or other suitable shapes and forms. In someembodiments, the densified intermediate material can be used as anengineered fuel feed stock in, for example, combustion power plants(e.g., coal burning power plants). In other embodiments, the densifiedintermediate material can be returned to the first conditioner 755A suchas to further incorporate the sorbent 790 (e.g., raise the sorbent 790content and/or rigidity within the pellet). With the desired amount ofsorbent 790 encapsulated within the plastics, a blower 770 can deliverthe densified intermediate material from the first densifier 731A to afirst pulverizer 733A.

The first pulverizer 733A can be any suitable device configured toreduce the densified intermediate material (e.g., pellets) to arelatively fine powder, such as about 3/32″ or 1/16″. With the densifiedintermediate material pulverized, a blower 770 can deliver thepulverized material to a third conditioner 755C. In some embodiments,the third conditioner 755C can be substantially similar to the firstconditioner 755A. Furthermore, the system 700 includes a second mixer754B configured to deliver a second waste stream from the materialclassification subsystem 720. In some embodiments, the second mixer 754Bcan be configured to mix a portion of soft plastics with a portion offibers. In other embodiments, the second mixer 754B is configured toonly mix soft plastics or fibers with the pulverized material. In thismanner, the third conditioner 755C is configured to condition (e.g.,heating, humidifying, and adding solutions) the pulverized material andthe soft plastics and/or fibers and deliver the conditioned materials tothe second densifier 731B.

In some embodiments, the second densifier 731B can be any suitabledensifier. In some embodiments, the second densifier 731B can besubstantially similar to the first densifier 731A. For example, in someembodiments, the second densifier 731B can be an extrusion deviceconfigured to apply a relatively high pressure to the materials suchthat the pulverized intermediate material (i.e. encapsulated sorbent andplastics) becomes encapsulated in the waste material (e.g., softplastics, and/or fibers). In this manner, the second densifier 731B canbe configured to produce an engineered fuel feed stock. In someembodiments, the fuel feed stock can be returned to the secondconditioner 755A such as to further incorporate the soft plastics and/orfibers or increase the pellets rigidity. This recirculation may beespecially necessary during the startup process of the production whenthe densifier is cool. With the desired amount of sorbent 790encapsulated within the waste material (e.g., hard plastics, softplastics, and/or fibers) a blower 770 can deliver the fuel feed stockfrom the second densifier 731B to a first pellet bunker 761. Expandingfurther, in some embodiments, the second densifier 731B can beconfigured to densify the material into an engineered fuel pellet. Insome embodiments, the engineered fuel pellets can be stored in the firstpellet bunker 761.

In some embodiments, it can be desirable to reduce the size of theengineered fuel pellets. In such embodiments, the blower 770 can beconfigured to deliver the engineered fuel pellets to a granulator 732.In this manner, the granulator 732 can reduce the size of the engineeredfuel pellets and produce a granulated fuel feed stock. The granulatedfuel feed stock can have an average particle size in the range of about0.04-0.2 inches for fluidized bed applications and in the range of about0.2-0.6 inches for circulating bed application. In some embodiments, thegranulated fuel feed stock can be delivered to a granulated fuel bunker763, as shown in FIG. 7. In other embodiments, it can be desirable tofurther reduce the size of the granulated fuel feed stock. In suchembodiments, a blower 770 can deliver the granulated fuel feed stock toa second pulverizer 733B. In this manner, the second pulverizer 733B canreduce the size of the granulated fuel feed stock to a relatively finefuel stock. The pulverized fuel feed stock can have an average particlesize in the range of about 0.004-0.12 inches. Furthermore, a blower 770can be configured to deliver the fuel stock powder to a powdered fuelbunker 765. Therefore, the system 700 can be configured to produce anengineered fuel feed stock for a variety of conditions (e.g., thepelletized fuel stock, the granulated fuel stock, and/or the pulverizedfuel stock).

FIG. 8 is a schematic illustration of a system 800 for producing anengineered fuel feed stock from solid waste material. The system 800includes a separation subsystem 815 and a fuel feed stock productionsubsystem 880 (also referred to herein as “Advanced ProductManufacturing” (APM) 880). The separation subsystem 815 can besubstantially similar to the separation subsystem 715 described abovewith respect to FIG. 7. Similarly, the APM 880 can include similarcomponents as the APM 780. Therefore, certain components of the APM 880are not described in detail herein and should be consideredsubstantially similar to the corresponding component of the APM 780unless explicitly described as different.

As shown in FIG. 8, the separation subsystem 815 can be configured toseparate the constituents of a waste stream. In this manner, theseparation subsystem 815 can include a set of bunkers configured tostore, for example, hard plastics, soft plastics, mixed plastics,fibers, and additives (e.g., any of the additives described above). Inthis manner, at least a portion of the waste stream can be delivered tothe APM subsystem 880 to produce an engineered fuel feed stock.Expanding further, in some embodiments, the separation subsystem 815 canbe configured to deliver a given quantity of the hard plastics, softplastics, mixed plastics, and/or additives to the EF subsystem 880. Insuch embodiments, the plastics (e.g., the hard and soft plastics) andthe additives are passed through metering devices 875 configured tocontrol the amount of the hard plastic, soft plastic, and/or additive tobe added to a first mixer 854A. The first mixer 854A can be any suitabledevice such as a paddled continuous mixer, a rotary continuous mixer, ascrew conveyor, an auger conveyor mixer, a mechanically vibrating mixer,and/or an agitating mixer. In this manner, the first mixer 854A can mixthe hard plastics, the soft plastics, and the additives and deliver theplastics and additives to a pre-treatment mechanism 856.

The pre-treatment mechanism 856 can be any suitable pre-treatmentmechanism such as, for example, the pre-treatment mechanism 756described above. The system 800 further includes a second mixer 854Bconfigured to receive the treated plastics and additives. Moreover, theseparation subsystem 815 can be configured to deliver a portion offibers to the second mixer 854B such that the fibers are mixed with thetreated plastics and additives. In this manner, a mixed waste stream(e.g., including the treated plastics and additives and the fibers) canbe delivered to a conditioner 855, as further described herein.

The conditioner 855 can be any suitable device and/or system configuredto condition at least a portion of the waste stream for engineered fuelfeed stock production. For example, in some embodiments, the conditioner855 can be configured to increase the temperature of the constituents ofthe waste stream (e.g., the fiber and the capsulated plastics/sorbent).In some embodiments, the conditioner 855 can be configured to increasethe moisture of the constituents of the waste stream.

The conditioner 855 can further be configured to deliver the conditionedwaste stream and additives to a densifier 831. The densifier 831 can beany suitable device configured to encapsulate at least a portion of theadditives into the plastics and fibers. For example, in someembodiments, the densifier 831 can be an extrusion device configured toapply a relatively high pressure (e.g., compress) to the mixture (e.g.,plastics, fibers, and additives) such that the additives become evenlydistributed (e.g., substantially homogenous) and/or encapsulated withinthe plastics and fibers. Furthermore, the densifier 831 can beconfigured to produce a densified intermediate material. The densifiedintermediate material can be in the form of cubes, briquettes, pellets,honeycomb, or other suitable shapes and forms. In some embodiments, thedensified intermediate material can be used as an engineered fuel feedstock in, for example, combustion power plants (e.g., coal burning powerplants). In other embodiments, the densified intermediate material canbe returned to the conditioner 855 such as to further incorporate theadditives and/or fibers. With the desired ratio of plastics, additives,and fibers produced a blower 870 can deliver a portion of the densifiedintermediate material from a bunker 861 for storage.

In some embodiments, it can be desirable to reduce the size of theintermediate material. In such embodiments, the blower 870 can beconfigured to deliver the engineered fuel pellets to a granulator 832.In this manner, the granulator 832 can reduce the size of the engineeredfuel pellets and produce a granulated fuel feed stock. In someembodiments, the granulated fuel feed stock can be delivered to agranulated fuel bunker 863, as shown in FIG. 8. In other embodiments, itcan be desirable to further reduce the size of the granulated fuel feedstock. In such embodiments, a blower 870 can deliver the granulated fuelfeed stock to a pulverizer 833. In this manner, the pulverizer 833 canreduce the size of the granulated fuel feed stock to a relatively finefuel stock. Furthermore, a blower 870 can be configured to deliver thefuel stock powder to a powdered fuel bunker 865. Therefore, the system800 can be configured to produce an engineered fuel feed stock for avariety of conditions (e.g., the pelletized fuel stock, the granulatedfuel stock, and/or the pulverized fuel stock).

As described above with reference to FIGS. 7 and 8, the engineered fuelfeed stock can contain any suitable ratio of sorbent. For example, FIG.9 shows an engineered fuel feed stock in various configurations. Morespecifically, a pelletized fuel stock 962A includes 40% hard plastic and60% sorbent. In some embodiments, a pelletized fuel stock 962B includes30% hard plastic and 70% sorbent. In some embodiments, a pelletized fuelstock 962C includes 20% hard plastic and 80% sorbent. In someembodiments, a pelletized fuel stock 962D includes 56% fiber, 14% hardplastic and 30% sorbent. In some embodiments, an engineered fuel feedstock includes about 5-50% sorbent and about 50-95% combustible material(i.e., fibers and plastics). The combustible material typically includesabout 60-80% fiber and about 24-40% plastics. While shown in FIG. 9 asincluding specific ratios, in some embodiments, an engineered fuel feedstock can be include any sorbent-material ratio and/or configuration.

As described herein, in some embodiments, a first waste stream can becombined with an additive material. The first waste stream can includehard plastic, soft plastic, or a mixed plastic material. For example,the first waste stream can be substantially all hard plastic. In someembodiments, the first waste stream includes at least about 80 wt. %, 90wt. %, or 95 wt. % hard plastic. In some embodiments, the first wastestream or can include less than about 40 wt. %, 30 wt. %, 20 wt. %, 10wt. %, or 5 wt. % soft plastic. In some embodiments, the first wastestream includes less than about 20 wt. %, 10 wt. %, or 5 wt. % fibers.In some embodiments, the first waste stream includes less than about 20wt. %, 10 wt. %, or 5 wt. % soft plastic and fiber in combination. Insome embodiments, the first waste stream is substantially free fromglass, metals, grit, and noncombustibles.

In some embodiments, the first waste stream and the additive arecompressed to form a densified intermediate material. The densifiedintermediate material can have a bulk density of between about 20 lb/ft³and about 60 lb/ft³. The additive can be a chemical additive such as,for example, a sorbent. In some embodiments, the sorbent can beformulated to adsorb at least one of the air pollutants including sulfurdioxide (SO2), sulfur trioxide (SO3), nitrogen oxides (NOx),hydrochloric acid (HCl), mercury (Hg), non-Hg metals and other hazardousair pollutants. For example, the additive can be sodium sesquicarbonate(Trona), sodium bicarbonate, sodium carbonate, zinc ferrite, zinc copperferrite, zinc titanate, copper ferrite aluminate, copper aluminate,copper managanese oxide, nickel supported on alumina, zinc oxide, ironoxide, copper, copper (I) oxide, copper (II) oxide, limestone, lime, Fe,FeO, Fe₂O₃, Fe₃O₄, iron filings, CaCO₃, Ca(OH)₂, CaCO₃.MgO, silica,alumina, china clay, kaolinite, bauxite, emathlite, attapulgite, coalash, egg shells, organic salts (such as calcium magnesium acetate (CMA),calcium acetate (CA), calcium formate (CF), calcium benzoate (CB),calcium propionate (CP) and magnesium acetate (MA)), urea, calciumbromide, sodium bromide, ammonium bromide, hydrogen bromide, ammoniumsulfate, Lignosulfonate, or Ca-montmorillonite.

As described herein, in some embodiments, the combined first wastestream and additive can be combined with a second and/or third wastestream to form an engineered fuel feed stock. For example, the secondwaste stream can include hard plastic, soft plastic, or mixed plasticand the third waste stream can include fibers. In some embodiments, thesecond waste stream includes plastics and fibers. In some embodiments,the second waste stream includes less than about 20 wt. %, 10 wt. %, or5 wt. % hard plastic. In some embodiments, the second waste streamincludes at least about 5 wt. %, 10 wt. %, or 20 wt. % soft plastic. Insome embodiments, the second waste stream includes at least about 80 wt.%, 90 wt. %, or 95 wt. % fibers. In some embodiments, the second wastestream includes at least about 95 wt. % soft plastic and fibers incombination. In some embodiments, the second waste stream issubstantially free from glass, metals, grit, and noncombustibles. Insome embodiments, the final engineered fuel feed stock can have a bulkdensity of between about 10 lb/ft³ and about 60 lb/ft³. In someembodiments, the final engineered fuel feed stock can have a bulkdensity of between about 20 lb/ft³ and about 40 lb/ft³.

As described herein, during the separation and classification process,various components of the waste streams can be shredded with a primaryshredder and optionally a secondary shredder. In some embodiments, thehard plastic component of the waste stream has an average particle sizeof less than about ½ inch, ⅜ inch, ¼ inch, 3/16 inch, ⅛ inch or 3/32inch. In some embodiments, the hard plastic component of the wastestream has an average particle size in the range between about 3/32 inchand about ¼ inch. In some embodiments, the hard plastic component of thewaste stream has an average particle size in the range between about3/32 inch and about ⅜ inch. In some embodiments, the hard plastic andsoft plastic components of the waste stream have an average particlesize in the range between about 3/32 inch and about ¾ inch. In someembodiments, the soft plastic component of the waste stream has anaverage particle size in the range between about ⅛ inch and about ⅜inch. In some embodiments, the fiber component of the waste stream hasan average particle size in the range between about ⅛ inch and about ⅜inch. In some embodiments, the fiber and soft plastic components of thewaste stream have an average particle size in the range between about ⅛inch and about ⅜ inch.

In some embodiments, the waste streams or individual components of thewaste stream are conditioned one more times during the engineered fuelfeed stock production process. For example, the conditioning can includeadding heat to raise the temperature of the waste stream, adding waterto raise the raise the moisture content of the waste stream, or addingsteam to raise the temperature and the moisture content of the wastestream. In some embodiments, the temperature of one or more of the wastestreams can be raised to about 300° F., 325° F., 350° F., or 375° F. Insome embodiments, the moisture content of one or more of the wastestreams can be raised to at least about 5%, 10% or 15%

As described herein, one or more waste streams can be combined with anadditive and then compressed to form a densified engineered fuel feedstock in a single pass (see, e.g., FIG. 8), or one or more waste streamscan be combined with an additive and then compressed to form a densifiedintermediate material, ground, and then combined with additional wastestreams before being compressed for second time to form a densifiedengineered fuel feed stock (see, e.g., FIG. 7). In some embodiments, thedensified intermediate material and/or the densified engineered fuelfeed stock can be ground (e.g., granulated or pulverized) to an averageparticle size of less than about ¾ inch, ⅝ inch, ½ inch, ⅜ inch, ¼ inch,3/16 inch, ⅛ inch, 3/32 inch.

As described herein, an engineered fuel feed stock made from a processedMSW waste stream can include a hard plastic content of between about 0wt. % and about 40 wt. %, a soft plastic content of between about 0 wt.% and about 40 wt. %, a fiber content of between about 30 wt. % andabout 80 wt. %, and a sorbent content of between about 5 wt. % and about50 wt. %. In some embodiments, the hard plastic content is between about0 wt. % and about 20 wt. %, between about 5 wt. % and about 20 wt. %,between about 10 wt. % and about 20 wt. %, between about 5 wt. % andabout 15 wt. %, or between about 10 wt. % and about 15 wt. %. In someembodiments, the soft plastic content is between about 0 wt. % and about20 wt. %, between about 5 wt. % and about 20 wt. %, between about 10 wt.% and about 20 wt. %, between about 5 wt. % and about 15 wt. %, orbetween about 10 wt. % and about 15 wt. %. In some embodiments, thefiber content is between about 30 wt. % and about 60 wt. %, betweenabout 40 wt. % and about 60 wt. %, or between about 40 wt. % and about50 wt. %. In some embodiments, the sorbent content is between about 10wt. % and about 40 wt. %, between about 20 wt. % and about 40 wt. %, orbetween about 30 wt. % and about 40 wt. %.

As described herein, an engineered fuel feed stock made from a processedMSW waste stream can include a mixed-plastic content of between about 10wt. % and about 40 wt. %, a fiber content of between about 30 wt. % andabout 80 wt. %, and a sorbent content of between about 5 wt. % and about50 wt. %. In some embodiments, the mixed-plastic content is betweenabout 0 wt. % and about 20 wt. %, between about 5 wt. % and about 20 wt.%, between about 10 wt. % and about 20 wt. %, between about 5 wt. % andabout 15 wt. %, or between about 10 wt. % and about 15 wt. %. In someembodiments, the fiber content is between about 30 wt. % and about 60wt. %, between about 40 wt. % and about 60 wt. %, or between about 40wt. % and about 50 wt. %. In some embodiments, the sorbent content isbetween about 10 wt. % and about 40 wt. %, between about 20 wt. % andabout 40 wt. %, or between about 30 wt. % and about 40 wt. %.

Examples

By way of example, a fuel production process can include passing a wastestream (e.g., hard plastics, soft plastics, and/or fibers) and additives(e.g., sorbents, biomass, biomaterials, and/or the like) through adensifier any number of times to incorporate the additive into wastematerial. Passing the waste stream/additive mixture through thedensifier multiple times increases the temperature of the constituentsto facilitate incorporation of the additive into the waste materialconstituents.

For example, approximately 20 wt. % of hard plastic and 80 wt. % ofsorbent (e.g., hydrated lime) were mixed and passed through a pelletizer10 times to produce densified pellets of hard plastic and sorbent inorder to observe the variation in physical properties of the hardplastic and/or sorbent, and determine the required temperature toproduce satisfactory fuel pellets. As indicated by the arrows NN and OOin FIG. 10, the mixture of the hard plastic and sorbent are shown aftera first, second, third, fourth, fifth, sixth, seventh, eighth, ninth,and tenth pass through the pelletizer. As shown, the sorbent, which is awhite powdery substance, is gradually incorporated after each passthrough the pelletizer. As described above, the temperature of themixture increases with each pass through the pelletizer, thus, alteringthe physical properties of the hard plastic and/or sorbent. Table 1below illustrates the temperature increase after each pass through adensifier:

TABLE 1 Temperature of # of Passes Densifier Temperature of Pellets 1173° Fahrenheit 110°-135° Fahrenheit 2 175° Fahrenheit 150°-180°Fahrenheit 3 179° Fahrenheit 180°-208° Fahrenheit 4 189° Fahrenheit217°-239° Fahrenheit 5 208° Fahrenheit 245°-262° Fahrenheit 6 212°Fahrenheit 276°-287° Fahrenheit 7 232° Fahrenheit 290°-310° Fahrenheit 8249° Fahrenheit 316°-323° Fahrenheit 9 281° Fahrenheit 337°-342°Fahrenheit 10 292° Fahrenheit 349°-357° Fahrenheit 11 310° Fahrenheit368°-374° Fahrenheit

As shown in FIG. 10, the sorbent is eventually incorporated into thehard plastic after 10 passes through the pelletizer (container in thelower right of FIG. 10). Although the process is shown and described inthis example as including 10 passes through a pelletizer, the processcan include more or fewer passes through a pelletizer or densifier. Forexample, the engineered fuel production process can include conditionersas described above to raise the temperature of the mixture prior todensification. In other examples, the sorbent can be selected togenerate heat when mixed with the waste materials and/or waiter (e.g.,quick lime).

The hard plastic pellets containing the sorbent (intermediate material)were then passed through a granulator to reduce the size of theengineered fuel pellets and produce a granulated fuel feed stock havingan average particle size in the range of about 0.004-0.04 inches. Thegranulated intermediate material (37.5 wt. % of total) was mixed with6.5 wt. % plastic and 56 wt. % fibers and passed through a pelletizer 10times to produce densified pellets of engineered fuel feed stockcontaining 14 wt. % plastic, 56 wt. % fiber and 30 wt. % sorbent. FIG.11 illustrates the mixture of the intermediate material (hard plasticand sorbent), soft plastic and, fiber after a first, second, third,fourth, fifth, sixth, seventh, eighth, ninth, and tenth pass through apelletizer (as indicated by the arrows PP and QQ) to form densifiedpellets of engineered fuel feed stock. The engineered fuel pellets canbe used in the pellet form, passed through a granulator to reduce thesize of the engineered fuel pellets and produce a granulated fuel feedstock having an average particle size of about 0.04 inches or in therange of about 0.008-0.12 inches, or passed through a pulverizer toreduce the size of the fuel feed stock to a relatively fine fuel stockhaving an average particle size of about 0.02 inches or in the range ofabout 0.008-0.08 inches.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Where methods described above indicate certain eventsoccurring in certain order, the ordering of certain events may bemodified. Additionally, certain of the events may be performedconcurrently in a parallel process when possible, as well as performedsequentially as described above.

Where schematics and/or embodiments described above indicate certaincomponents arranged in certain orientations or positions, thearrangement of components may be modified. Similarly, where methodsand/or events described above indicate certain events and/or proceduresoccurring in certain order, the ordering of certain events and/orprocedures may be modified. While the embodiments have been particularlyshown and described, it will be understood that various changes in formand details may be made.

For example in reference to FIG. 7, while specific waste streams aredescribed as entering the first mixer 754A and the second mixer 754B,the waste streams can be introduced to the first mixer 754A or secondmixer 754B in any given configuration. For example, in some embodiments,the first mixer 754A can be configured to receive only hard plastics,only soft plastics, and/or any suitable combination of hard plastics andsoft plastics. Similarly, in some embodiments, the second mixer 755B canbe configured to receive only soft plastics, only fibers, and/or anysuitable combination of soft plastics and fibers. Furthermore, the anyconstituent configuration of the first mixer 754A can be used with anyconstituent configuration of the second mixer 754B.

Although various embodiments have been described as having particularfeatures and/or combinations of components, other embodiments arepossible having a combination of any features and/or components from anyof embodiments as discussed above.

What is claimed is:
 1. A method of producing an engineered fuel feedstock from a processed MSW waste stream, the method comprising:combining a first waste stream and an additive; compressing the firstwaste stream and the additive to form a densified intermediate material;grinding the intermediate material; mixing the ground intermediatematerial with a second waste stream; and compressing the intermediatematerial and the second waste stream to form an engineered fuel feedstock.
 2. The method of claim 1, wherein the first waste stream includeshard plastic.
 3. The method of claim 2, wherein the first waste streamcontains less than about 40 wt. % soft plastic. 4.-7. (canceled)
 8. Themethod of claim 3, wherein the first waste stream contains less thanabout 20 wt. % fiber.
 9. (canceled)
 10. (canceled)
 11. The method ofclaim 3, wherein the first waste stream contains less than about 20 wt.% soft plastic and fiber in combination. 12.-16. (canceled)
 17. Themethod of claim 2, wherein the first waste stream is substantially freefrom glass, metals, grit, and noncombustibles. 18.-22. (canceled) 23.The method of claim 2, wherein the densified intermediate material has aplastic content of between about 10 wt. % and about 50 wt. %; and anadditive content of between about 90 wt. % and about 50 wt. %. 24.(canceled)
 25. The method of claim 1, wherein the additive is a chemicaladditive.
 26. The method of claim 25, wherein the chemical additive is asorbent.
 27. The method of claim 26, wherein the sorbent is formulatedto adsorb at least one of the air pollutants including sulfur dioxide(SO2), sulfur trioxide (SO3), nitrogen oxides (NOx), hydrochloric acid(HCl), mercury (Hg), non-Hg metals and other hazardous air pollutants.28. The method of claim 1, wherein the additive is at least one ofsodium sesquicarbonate (Trona), sodium bicarbonate, sodium carbonate,zinc ferrite, zinc copper ferrite, zinc titanate, copper ferritealuminate, copper aluminate, copper managanese oxide, nickel supportedon alumina, zinc oxide, iron oxide, copper, copper (I) oxide, copper(II) oxide, limestone, lime, Fe, FeO, Fe₂O₃, Fe₃O₄, iron filings, CaCO₃,Ca(OH)₂, CaCO₃.MgO, silica, alumina, china clay, kaolinite, bauxite,emathlite, attapulgite, coal ash, egg shells, organic salts (such ascalcium magnesium acetate (CMA), calcium acetate (CA), calcium formate(CF), calcium benzoate (CB), calcium propionate (CP) and magnesiumacetate (MA)), urea, calcium bromide, sodium bromide, ammonium bromide,hydrogen bromide, ammonium sulfate, Lignosulfonate andCa-montmorillonite.
 29. The method of claim 1, wherein the second wastestream includes at least one of hard plastic, soft plastic and fibers.30.-36. (canceled)
 37. The method of claim 29, wherein the second wastestream contains at least about 80 wt. % fiber.
 38. (canceled) 39.(canceled)
 40. The method of claim 29, wherein the second waste streamcontains at least about 95 wt. % soft plastic and fiber in combination.41. The method of claim 29, wherein the second waste stream issubstantially free from glass, metals, grit, and noncombustibles. 42.The method of claim 29, wherein the second waste stream has a softplastic content of between about 0 wt. % and about 20 wt. %; and a fibercontent of between about 80 wt. % and about 100 wt. %. 43.-197.(canceled)
 198. The method of claim 1, wherein the engineered fuel feedstock includes about 5 wt. % to about 50 wt. % of the additive and about50 wt. % to about 95 wt. % combustible material.
 199. The method ofclaim 198, wherein the combustible material includes fibers andplastics.
 200. The method of claim 199, wherein the combustible materialincludes about 60 wt. % to about 80 wt. % fiber and about 24 wt. % toabout 40 wt. % plastics.
 201. The method of claim 198, wherein theadditive is a sorbent.